Stratigraphic layering is a process used in the modeling of the earth for geoscience purposes whereby an earth model is enhanced by introducing layers between correlated sequence boundaries to increase the resolution of the model. A depositional sequence is a stratigraphic unit composed of genetically related strata that is bounded at its top and base by unconformities or their correlative surfaces.
An earth model with stratigraphic layering can be used for high-resolution facies and/or property modeling. One goal of stratigraphic layering is to create a high-resolution subdivision of a sequence which properly reflects the internal layering of the sequence. Examples of existing approaches to stratigraphic layering are shown in FIGS. 1-3, which show an area-depth representation of a sequence bounded by an upper sequence boundary 105 and a lower sequence boundary 110. In top down stratigraphic layering, illustrated in FIG. 1, the introduced layers, e.g. 115, are parallel to the top sequence boundary 105. In bottom up stratigraphic layering, illustrated in FIG. 2, the introduced layers, e.g. 205, are parallel to the bottom sequence boundary 110. In proportional stratigraphic layering, illustrated in FIG. 3, each of the introduced layers, e.g. 305, varies in width. The width d of each introduced layer at any given point p is proportional to the distance D between the sequence boundaries at that point.
Harry E. Wheeler, in an article entitled Baselevel, Lithosphere Surface, and Time-Stratigraphy, GEOLOGICAL SOCIETY OF AMERICA BULLETIN, v. 75, pp. 599-610 (July 1964) (hereinafter “Wheeler Article”), described a way to show sequences in area-time rather than the traditional area-depth view. In the area-time view, which will be referred to as Wheeler Space, “the vertical dimension is time [rather than depth] and . . . all lithosphere surface-moments expressing the succession of events are horizontal and parallel.” Wheeler Article at 606.